Gazelle March 2002

Contents:

Where to find us

The DNHG's monthly lectures are now held at The Emirates Academy of
Hospitality Management, located opposite "Wild Wadi" near the Burj
Al-Arab and the Jumeirah Beach Hotel. The Emirates Academy features a 140-seat
auditorium, excellent acoustics and a built-in audio-visual system.

The auditorium is adjacent to the main entrance, on the Beach Road side. The
Academy facade resembles an Arabic fortress, with four flags flying at the front
gate. These are normally illuminated at night. The complex is visible from Beach
Road but is set back about 100 yards from the road and is now partly obscured by
construction. Direct access is currently over an open lot; for easiest access,
it is best to follow the map on page 7. There is a paved parking lot within the
gates.

Members who are coming to lectures directly from work may find it convenient
to take advantage of the cafeteria located on the Emirates Academy premises, on
the left of the outdoor courtyard behind the main lobby. Non-members are always
welcome at the monthly lectures, too. Just come along. The lecture starts
promptly at 8.00pm, so if you'd like to eat or chat first, come well before
then.

Jebel Ghaweel Hike

Report by Gary Feulner

Jebel Ghaweel is a three-peaked ridge on the mountain front east of Al-Hayer,
distinctive by virtue of its summit cap of white limestone, an
"exotic" block, probably a former atoll that was carried along atop
the deep ocean sediments and volcanics that were bulldozed and deformed ahead of
the advancing ophiolite. The triple summits are the Hajar Mountain's answer to
Italy's Dolomites, complete with sheer faces and craggy spires. The summit
profile is daunting and, looking up, it was hard to believe what we were going
to do.

As advertised, highlights included unusual rocks and plants. On the way up we
stopped to look at turbidites (deep ocean sediments deposited from turbidity
currents and having a graded structure), as well as volcanic rocks identifiable
by their many tiny air pockets (vesicles) filled by later stage white minerals,
and, near the summit, yellow-green veins of chlorite, many of which seem to have
been the site of fracturing and movement within the deformed rocks. We also saw
a number of dwarf rock geckoes, Pristurus rupestris and the larger
P. celerrimus, which signal with their tails. As usual, about half
of these seemed to have lost and regrown their original tails.

The environment was very dry, but not devoid of botanical interest. Special
attractions included the wild olive, found only at higher elevations, the sidr
tree (Zizyphus spina-cristi) in fruit (but undesirably astringent,
was the gastronomic verdict) as well as several of the region's hanging or
climbing plants. The cliff-dwelling Capparis cartinagenia is
related to the edible caper. Another prominent cliff plant, Cocculus
pendulus, sported small berries. Richard Dennis was game to sample them,
but Gary Feulner suggested otherwise, given that the species belongs to the
curare family. The climbing milkweed Pentatropis nivalis had found
its way into a small Moringa (broom tree) whereas the leafless climber Ephedra
aphylla was mostly seen on Jebel Ghaweel as an erect shrub, and was
found climbing into only one small Desert Thorn (Lycium shawii).
We saw no goats at all, and the presence of a number of larger Desert Thorn
shrubs indicates that grazing pressure may have been reduced for the past few
years.

Despite the drought, we found a number of specialized plant species in flower
from time to time, in favorable locations, including a thriving Euphorbia
larica (the "donkey-sat-on-it" bush) and the cactus-like Caralluma
arabica. Moriga peregrina, the broom tree, was in full
bloom at lower elevations and Martina Fella spied a pair of Purple Sunbirds
feeding on the nectar in one large tree, perhaps preparing to nest. Other bird
life included a few sand partridges, Hume's wheatear in song, and, at the
summit, a pale crag martin surfing enviably on the updrafts and a Bonelli's
eagle soaring overhead. Encouraged by Gary, Martina also spotted the first of
many of the rare bullet-shaped striped land snails, Pseudonapaeus
jousseaumei, found in the wild only at higher elevations in the Hajar
range and the Jebel Akhdar in Oman.

Lunch was served at the summit by Martina, in true Emirates in-flight style,
but we all wondered how she had managed to pack so much junk food – sausage,
potato chips, candies, even Hostess twinkies -- into such a small backpack. Mike
Lorrigan, for his part, served sandwiches all around, prepared in a burst of
early morning Boy Scout zeal. The lunch site gave a marvelous view of the
surrounding countryside, from Jebel Hatta and the Hajar range to Buraimi to the
south and the desert to the west, and showed off other, smaller hills capped by
similar white exotic blocks.

After summiting, we walked the summit ridge to the east end and looked back.
It appeared so rugged and difficult, we could hardly believe we had been there.
So, as a special treat for this strong hiking group (Martina was hiking in boots
with soles taped on enroute by Richard's emergency repair tape), the decision
was made to descend via a "new" route down a wadi that cut through
several vertical limestone ridges. There were some second thoughts as the chute
narrowed and steepened, but these passed after we saw several small cairns
indicating that this had once been an "established" route. The route
was in need of resurfacing, however, and we worked our way down carefully over
slopes covered with bits and blocks of broken limestone. David Palmer said
afterwards that he felt like he had been skiing.

We returned to the cars, about nine hours and many rolls of film after we had
left them, and looked back up at the jagged skyline, now silhouetted by the
dying sun. We still couldn't believe we had done "that."

Snakes: Cause for concern?

Report by Peter Cunningham

Most people are more afraid of snakes than weapons or other people. This is
understandable as certain snakes are venomous and can cause fatalities, but the
probability of being fatally bitten by a snake is low. The following table was
published in the New Scientist of 3 March 2001 and indicates potential cause of
human death and the probability of being affected.

Cause of death

Probability

Traffic accident

1 in 100

Murder

1 in 300

Fire

1 in 800

Firearms accident

1 in 2500

Electrocution

1 in 5000

Passenger aircraft crash

1 in 20 000

Asteroid or comet impact

1 in 20 000

Flood

1 in 30 000

Tornado

1 in 60 000

Venomous bite or sting

1 in 100 000

Firework accident

1 in 1 million

Food poisoning by botulism

1 in 3 million

[Now of course everything is relative, for instance, if you find yourself
unlucky enough to be in Angola the probability of being blown up by a landmine
would be quite high]

Twenty-one species of snakes belonging to 6 families occur (including
offshore) in the UAE. Of these, only four terrestrial species (Family Viperidae
- True Vipers) and eight marine species (Family Hydrophiidae) are potentially
dangerous.

Of the four Viper species found in the UAE the Saw-scaled Viper (Echis
carinatus) is potentially the most dangerous with case fatalities reported as
5-10% in hospitalized cases. Saw-scaled Viper venom is haemotoxic or
vasculotoxic causing local pain and swelling and widespread bleeding. Carpet
Viper (Echis coloratus) and Sand Viper (Cerastes cerastes) venom is potentially
dangerous although symptoms are less severe than for the Saw-scaled Viper and
fatalities are rare. Very little is known about the False-horned Viper
(Pseudocerastes persicus), a potentially dangerous snake of high altitudes, but
rarely encountered. Sea snake bites are not painful and 50% of bites do not
result in envenoming. The venom is neurotoxic and results in muscle paralysis.

Bites of the rear-fanged Colubrids, mildly toxic and/or harmless snakes, may
occasionally result in envenoming with pain and local swelling being common. As
a general rule-of-thumb in the UAE, snakes, which are long and slender, are
harmless while short and stocky snakes are potentially dangerous.

First Aid

Evacuation of the unfortunate person to the nearest hospital or clinic (most
large hospitals and clinics have anti-venom) is advisable, especially if bitten
by a potentially dangerous or unidentified snake. A pressure bandage (splint
limb if possible) should be wrapped around the bitten limb and mobility
restricted where possible resulting in delaying the absorption of venom.
Fortunately bites of venomous snakes encountered in the UAE rarely develop
irreversible life-threatening situations within six hours.

Snakes are extremely beautiful and interesting creatures certainly not out to
"get" humans or afflicted with the devil. In fact most snakes I have
encountered are passive and only strike or try and defend themselves when
actively harassed. In all cases the snakes have always tried to escape before
attempting to defend themselves. Inflating the body and rubbing the scales on
the flanks together causes the early warning rasping sound used by Saw-scaled
Vipers. An interesting theory exists that this warning sound has evolved in an
arid environment instead of hissing, which results in the loss of water vapor. A
quote by an anonymous source I came across recently sums it up: " We only
conserve what we love. We only love what we know. We only know what we are
taught."

Beware! Alien Invaders!

Report by Peter Cunningham

Non-native or alien species can and do cause considerable damage to the host
environment they find themselves in, usually at the expense of native wildlife.
It was pointed out recently at the United Nations Biodiversity Convention in
Montreal, Canada, that alien species are the second biggest threat to indigenous
wild species after habitat loss. Alien species often out-compete native species
for resources, introduce diseases or inter-breed resulting in a loss of species
diversity and a general loss of biodiversity.

The UAE has its fair share of alien species and related problems. These range
from donkeys, archaic transport, to unwanted pets released into the wild by
"caring" owners such as Mollies (ornamental fish). Feral donkeys
compete directly with the declining Gazelle and Tahr for grazing, which is often
marginal, in mountainous areas. Feral cats and dogs also account for a
substantial loss of native birds, reptiles and small mammals and is arguably not
too difficult to control as other problem species.

According to the UNEP (United Nations Environment Programme) alien fish
species threaten 20% of the world's freshwater fish with extinction. Locally the
predatory fish, Tilapia (Oreochromis spp.), have been released as a source of
food in local Wadi systems to the detriment of indigenous species such as the
Arabian Killifish (Aphanius dispar), a predator of mosquito larvae.

Birds such as the Myna's of which 3-4 species are breeding residents to the
Emirates, Masked, Streaked & Golden-backed Weavers, Scaly-breasted Munia,
Red Avadavit and Pin-tailed Whydah, to mention but a few, often out-compete
native species for food, nesting material and nesting space. Recently the
beautiful and vocal Indian ring-necked parakeet has been cited as a source of
influenza A viruses liable to infect chickens, mice and ultimately humans. Bird
flu has caused recent human fatalities in Hong Kong (1999) and China (2000). The
deadly Spanish flu epidemic in 1918 resulted in the death of 40 million people
world-wide. Other flu epidemics in 1957 and 1968 killed over a million people.
Unwanted pet birds should not be released into the wild so as to avoid
above-mentioned disasters.

Fifteen species of introduced ants (20% of all ant species recorded in the
UAE) have been recorded from the Emirates with 3 species posing potential
problems as public health and nuisance pests while 2 species threaten the local
entomo-fauna and biodiversity. In the southern USA an alien ant species was so
successful that it almost entirely out-competed the local ant fauna and altered
the local insect diversity. Controlling ants and other alien arthropods is also
very difficult, time consuming and expensive.

Exotic trees such as Eucalyptus (Blue-gum spp.) generally use more water than
indigenous species while exotic Prosopis spp. have the potential of invading
marginal areas and ousting local flora, which is evident (in its initial phase)
in the RAK and Fujairah coastal areas.

Many countries don't often realize the threats posed by alien species and
that they can be eradicated. Feral cats and rats (both of which prey heavily on
birds) are 2 species that have been successfully eradicated from island off
South Africa and New Zealand.

Authorities should implement better monitoring, quarantine and overall
environmental control to prevent exotic species from becoming a problem.
"Do-gooders" should also realise that releasing those unwanted pets
may cause more damage than good when released into an unfamiliar environment.
Pet shop owners and other importers of exotic wildlife as well as illegal
trafficking in live and other animal products should be eradicated and strictly
controlled by the relevant authorities so as to avoid the type of publicity such
as was recently published in New Scientist (10 March 2001). "Indian ivory
joins African ivory before it goes to Japan or China. The biggest smuggling
route out of India is through the UAE, and African ivory always comes that
way".

Spiny-tail Lizards suffering from lack of rain

Report by Peter Cunningham

Peter Cunningham has monitored twenty Spiny-tail Lizard individuals since May
1999 in the Al Ain area as part of his requirements for a Ph.D. study on the
conservation ecology of the species that he is currently busy with. Since the
start of the study no rain has fallen in the study area. This, coupled with a
large number of camels in the area, has resulted in the visible decline of the
desert vegetation. The coarse desert grass, Pennisetum divisum, which is a
favored plant utilized by the Spiny-tail's, have been particularly badly
affected. Between May 1999 and June 2000 11 individuals had succumbed indicating
a 55% mortality rate over a 1-year period. In another study area where
Moltkiopsis ciliata, of the Borage family, is the dominant plant, the
Spiny-tail's are faring much better with no fatalities since January 2000.
Moltkiopsis ciliata is closely cropped through active browsing by Spiny-tail's
making it unavailable to camels. The Moltkiopsis area is a favoured habitat with
a high density (±10 individuals per hectare) of Spiny-tail's in the area.

Very little work has been done on the diet of Spiny-tail Lizards throughout
their range. During my current research, ten perennial plant species from 8
different families have been identified as being included in their diet. These
include species from the Milkweed, Pea and Gourd family, to name but a few.
Interestingly the Desert Squash, Citrullus colocynthis, is also eaten. It is
expected that many more plant species, especially annuals, would be consumed
once (if) the rains arrive.

Another interesting aspect is that the majority of burrows face in a
southerly and easterly direction. During summer this makes sense as burrows
facing in a northerly and westerly direction would be warmer and receive more
windblown sand, as the prevailing wind is northwest during summer.

It has also been determined that the burrow temperatures are on average 6°C
cooler than the ambient temperature 30cm below ground. This is significant when
ambient temperatures are regularly in the mid-to-high 40°C during summer with
soil temperatures above 60°C.

The author would welcome any other interesting data concerning Spiny-tail
Lizards as observed by members. If any Spiny-tail Lizard road-kills are
encountered please collect, freeze and inform Peter whereupon he will come and
collect it.

Tahr on Jebel Hafit

Report by Peter Cunningham

During a hike up to the summit wadi's on Jebel Hafit during October I
witnessed a rare event that made the unusual heat for this time of the year more
bearable. An adult male Tahr emerged unexpectedly out of a gully approximately
100m ahead of me. Recognizing it immediately I knew how privileged I was to see
this rare ungulate in its natural environment.

Arabian Tahr, Hemitragus jayakari, are endemic to the Arabian Peninsula and
occur in mountainous terrain throughout the eastern UAE and northern Oman, from
the Musandam in the north to the mountains bordering the Wahiba Sands in the
south. The well-known Arabian explorer, Wilfred Thesiger, first documented them
from Jebel Hafit in 1949 and mentions them being regularly hunted by local Bedu
during that time. According to a study conducted on this species in Oman in the
late 70's, the Arabian Tahr world population did not exceed 2000 animals. A
helicopter survey of Jebel Hafit in 1980 sighted only 5 animals. During the 80's
they were thought to be extinct on Jebel Hafit as no sightings were reported.
Confirmed sightings are infrequent and they are classified as "critically
endangered" (i.e. "facing an extremely high risk of extinction in the
wild in the immediate future") in the UAE.

This little known species is in direct competition with domestic and feral
goats for the available food. They are highly selective feeders mainly utilizing
the growth tips and fruits of certain shrubs. The carrying capacity of mountains
such as Jebel Hafit is generally low and the extra pressure of hunting (now
illegal although not enforced) and excessive goat numbers could lead to the
demise of this species in the wild if something drastic is not done to protect
them.

The individual I encountered was typical of males of the species with its
well-developed forequarters, prominent facial stripe, thick slightly curved
horns and dark-brown shaggy coat [A previous sighting I had of a female in the
Central Hajar Mountains had an overall slender build and "blonder"
appearance]. Initially it was unaware of me as I had the wind in my favor and
had approached the rise I was on with care. As soon as I moved to get my camera
from my backpack it sensed me and loped off - not fleeing in fear - up the
mountain towards some inaccessible cliffs where I could not follow. As I was not
expecting to stumble upon Tahr, I was unprepared, but did eventually (after
having to change lenses in haste) get two photos of the Tahr just before it
disappeared over the crest. Unfortunately the distance involved as well as
midday lighting did not make for a great photo and I am now trying to get the
subject enlarged. Although not detracting from the actual encounter of observing
Tahr at such close quarters, one thing I did however learn is to always be
prepared for the unexpected - next time!